Search NASA⌕ Search

SEARCH · Search NASA

Results for “SPACE ERECTABLE STRUCTURE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

172 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

The middeck 0-gravity dynamics experiment

The Middeck 0-Gravity Dynamics Experiment (MODE), flown onboard the Shuttle STS-48 Mission, consists of three major elements: the Experiment Support Module, a dynamics test bed providing computer experiment control, analog signal conditioning, power conditioning, an operator interface consisting of a keypad and display, experiment electrical and thermal control, and archival data storage: the Fluid Test Article assembly, used to investigate the dynamics of fluid-structure interaction in 0-gravity; and the Structural Test Article for investigating the open-loop dynamics of structures in 0-gravity. Deployable, erectable, and rotary modules were assembled to form three one- and two-dimensional structures, in which variations in bracing wire and rotary joint preload could be introduced. Change in linear modal parameters as well as the change in nonlinear nature of the response is examined. Trends in modal parameters are presented as a function of force amplitude, joint preload, and ambient gravity. An experimental study of the lateral slosh behavior of contained fluids is also presented. A comparison of the measured earth and space results identifies and highlights the effects of gravity on the linear and nonlinear slosh behavior of these fluids.

Crawley, Edward F.↗
NASA NTRS1991

Optimization techniques applied to passive measures for in-orbit spacecraft survivability

Spacecraft designers have always been concerned about the effects of meteoroid impacts on mission safety. The engineering solution to this problem has generally been to erect a bumper or shield placed outboard from the spacecraft wall to disrupt/deflect the incoming projectiles. Spacecraft designers have a number of tools at their disposal to aid in the design process. These include hypervelocity impact testing, analytic impact predictors, and hydrodynamic codes. Analytic impact predictors generally provide the best quick-look estimate of design tradeoffs. The most complete way to determine the characteristics of an analytic impact predictor is through optimization of the protective structures design problem formulated with the predictor of interest. Space Station Freedom protective structures design insight is provided through the coupling of design/material requirements, hypervelocity impact phenomenology, meteoroid and space debris environment sensitivities, optimization techniques and operations research strategies, and mission scenarios. Major results are presented.

Mog, Robert A.↗
NASA NTRS1982

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Heard, W. L., Jr.↗
NASA NTRS1981

Structural sizing considerations for large space structures

A number of missions for the space shuttle were proposed which involve placing large truss platforms on-orbit. These platforms range in size from tens of meters in span for reflector application to several thousand meters for solar power collector application. These proposed sizes and the operational requirements considered are unconventional in comparison to Earthbound structures and little information exists concerning efficient proportions of the structural elements forming the framework of the platforms. Such proportions are of major concern because they have a strong influence on the packaging efficiency and, thus, the transportation effectiveness of the shuttle. The present study is undertaken to: (1) identify efficient ranges of application of deployable and erectable platforms configured for shuttle transport to orbit, and (2) determine sensitivity to key parameters of minimum mass deployable and erectable platform designs.

Heard, W. L., Jr.↗
NASA NTRS1991

Concepts, analysis and development for precision deployable space structures

Several issues surrounding the development of large Precision Segmented Reflector (PSR) designs are investigated. The concerns include nonlinear dynamics of large unruly masses such as the multi-layer thermal insulation of sunshades for instruments such as the precision pointing 20-m-diameter Large Deployable Reflector (LDR). A study of the residual oscillations after bang-bang reorientation maneuvers of a rigid satellite with a string appendage is presented. Application is made to the design of a sunshade (thermal blanket) for the LDE satellite. Another concern is the development of a deployable truss that has minimum structural redundancy (such as the tetrahedral truss) and that can be configured with planar and doubly curved geometries. A kinematically synchronized articulation scheme for a deployable tetrahedral truss is presented. Called the Tetrapac, this truss is currently limited to a planar configuration that has two rings. The final concern is the development and demonstration of hardware that enables astronauts to attach large, cumbersome, and fragile precision reflector segments to an erectable truss structure. This task must be accomplished with a high degree of precision and with relative ease. A design for a Panel Attachment Device (PAD) was developed and manufactured for neutral buoyancy simulations to be performed by LaRC.

Miller, Richard K.↗
NASA NTRSDate not supplied

Structural Architectures for Self-Erecting Lunar Towers

The load carrying performance for deployable lunar tower architectures utilizing thin-ply composite booms are parametrically evaluated in this paper. These self-erecting towers support a communications and sensor platform on the lunar surface. The primary design consists of the Corrugated Rollable Tubular Boom (COROTUB) acting as the primary mast of the tower which supports the payload tip mass. Guy wires connecting the boom tip to spreader bars attached at the base deployer serve to correct any lateral eccentricities and provide dimensional stability. The analysis compares the maximum tip mass that this primary design can carry relative to a reference design that does not contain any guy wires or spreader bars. The results provide insights into whether the additional system mass and complexity associated with the cable-stayed design is worth the increased payload mass that can be supported. By setting the design limiting condition to a nominal maximum allowable deflection, the analysis reveals that primary design outperforms reference design for the majority of the design space. This outcome is found to be the case when the spreader bar length relative to the tower height exceeds7 a critical value. The analysis is extended to lunar towers with Collapsible Tubular Mast (CTM) booms, and similar trends are observed.

Jacob G Daye↗
NASA NTRSDate not supplied

Structural Architectures for Self-Erecting Lunar Towers

The load carrying performance for deployable lunar tower architectures utilizing thin-ply composite booms are parametrically evaluated in this paper. These self-erecting towers support a communications and sensor platform on the lunar surface. The primary design consists of the Corrugated Rollable Tubular Boom (COROTUB) acting as the primary mast of the tower which supports the payload tip mass. Guy wires connecting the boom tip to spreader bars attached at the base deployer serve to correct any lateral eccentricities and provide dimensional stability. The analysis compares the maximum tip mass that this primary design can carry relative to a reference design that does not contain any guy wires or spreader bars. The results provide insights into whether the additional system mass and complexity associated with the cable-stayed design is worth the increased payload mass that can be supported. By setting the design limiting condition to a nominal maximum allowable deflection, the analysis reveals that primary design outperforms reference design for the majority of the design space. This outcome is found to be the case when the spreader bar length relative to the tower height exceeds a critical value. The analysis is extended to lunar towers with Collapsible Tubular Mast (CTM) booms, and similar trends are observed.

Jacob G Daye↗
NASA NTRS1986

Development of composite tube protective coatings

Protective coatings for graphite/epoxy (Gr/Ep) tubular structures proposed for the Space Station are evaluated. The program was divided into four parts; System Definition, Coating Concept Selection and Evaluation, Scale-up and Assembly, and Reporting. System Definition involved defining the structural and environmental properties required of the Gr/Ep tubes. The prepreg and ply sequence selected was a P75S/934 (O2, + or - 20, O2)sub s layup which meets the various structural requirements of the Space Station. Coating Concept and Selection comprised the main emphasis of the effort. Concepts for protectively coating the Gr/Ep tubes included the use of metal foil and electroplating. The program results demonstrated that both phosphoric and chromic acid anodized Al foil provided adequate adhesion to the Gr/Ep tubes and stability of optical properties when subjected to atomic oxygen and thermal cycling representative of the LEO environment. SiO2/Al coatings sputtered onto Al foils also resulted in an excellent protective coating. The electroplated Ni possessed unacceptable adhesion loss to the Gr/Ep tubes during atomic oxygen testing. Scale-Up and Assembly involved fabricating and wrapping 8-ft-long by 2-in-diameter Gr/EP tubes with chromic acid anodized foil and delivering these tubes, along with representative Space Station erectable end fittings, to NASA LaRC.

Dursch, H.↗
NASA NTRS2008

Deployable Crew Quarters

The deployable crew quarters (DCQ) have been designed for the International Space Station (ISS). Each DCQ would be a relatively inexpensive, deployable boxlike structure that is designed to fit in a rack bay. It is to be occupied by one crewmember to provide privacy and sleeping functions for the crew. A DCQ comprises mostly hard panels, made of a lightweight honeycomb or matrix/fiber material, attached to each other by cloth hinges. Both faces of each panel are covered with a layer of Nomex cloth and noise-suppression material to provide noise isolation from ISS. On Earth, the unit is folded flat and attached to a rigid pallet for transport to the ISS. On the ISS, crewmembers unfold the unit and install it in place, attaching it to ISS structural members by use of soft cords (which also help to isolate noise and vibration). A few hard pieces of equipment (principally, a ventilator and a smoke detector) are shipped separately and installed in the DCQ unit by use of a system of holes, slots, and quarter-turn fasteners. Full-scale tests showed that the time required to install a DCQ unit amounts to tens of minutes. The basic DCQ design could be adapted to terrestrial applications to satisfy requirements for rapid deployable emergency shelters that would be lightweight, portable, and quickly erected. The Temporary Early Sleep Station (TeSS) currently on-orbit is a spin-off of the DCQ.

Izenson, Michael G.↗
NASA NTRS2004

Co-axial Joint Technology Applied to Antenna Backup Structures

The increasing demand to improve focusing accuracy and to accommodate higher frequencies in space communications and radio astronomy has created significant challenges for improving the capability of the constituent systems in radio antennas and telescopes. One important system is the radio antenna/telescope backup structure connections. The backup structure is a key element in providing a stable, precise and rigid support for the reflective surface. The ideal connection for these types of structures is rigid and concentric resulting in minimal deformation with stress/strain curves that are linear, repeatable and exhibiting no hysteresis over the entire service load range. Conceivably such a connection could be designed so that the stress/strain curve mimics the stress/strain characteristics of the connecting member in both tension and compression. When this is achieved then such joints can be said to be 'invisible' in the global behavior of the backup structure. At that point, overall reflector deflection becomes more linear and highly predictable. In conjunction with this advantage, optimized backup structure geometries, adaptive reflectors and compensating algorithms can best be applied in producing an instrument of unparalleled performance. This paper introduces Co-Axial Joint (CAJ) technology as the practical and economical means to produce an invisible connection.

trusses↗